With the recent advancements in miniaturization of semiconductor device, defects due to variation of manufacturing or particles increase, so that it is very difficult to improve a yield rate. A method for shortening the wavelength of light source (exposure light rays) and a method for increasing the numerical aperture (NA) of lens cannot catch up with the miniaturization of semiconductor device which advances at an accelerated pace. In such a conventional technique, it is desired that a post-process dimension of a pattern is predicted at a high degree of accuracy regardless of the shape of the pattern.